ABSTRACT:
Aim: To write a review on hormones influencing growth of the fetus. Background: The metabolic adaptations of pregnancy are regulated by hormones produced by placental and maternal pituitary glands. They regulate key physiological events essential for maintaining pregnancy and developing fetus for extra uterine life. Hormones influencing foetal growth are released by mother, placenta and foetus; they belong to growth hormone (GH)/ prolactin gene family, placental lactogens( PL) and prolactin related hormones. Placental hormones are peptides such as Chorionic Gonadotropins, placental lactogens; or Steroids such as Progestogens and Estrogens. In Primary Congenital Hypothyroidism (CH), the baby is born normal, but shows signs of hypothyroidism later. Deficiency of Human Chorionic Somatomammotropin results in decreased placental weight associated with Intra Uterine Growth Restriction (IUGR) leading to low birth weight babies. Studies have shown maternal deficiency of GH and thyroid hormones may not affect prenatal size of foetus. However, mutation of IGF I in mother inhibits GH action resulting in Small For Dates babies despite normal gestation period. These babies are immediately treated with Growth Hormone therapy on birth. Reason for the review: To have a better understanding of the close communication between placenta and foetus, involving complex physiological developmental regulatory mechanisms.